Electrical connector

Abstract: This invention prevents terminals 4 and 5 from being abraded or ground at contacting portions due to vibrations. An end of a male terminal 5 is secured in a part of a stepped hole 16 in a rear wall portion 12 and the other end of the terminal 5 is coupled to a female terminal 4. Even if the female terminal 4 is displaced due to vibrations in a coupled position relative to the male terminal 5, the male terminal 5 can elastically deflect in another part of the stepped hole 16 in accordance with a displacement of the female terminal 4. Consequently, an abnormal contacting pressure caused by vibration at contacting portions of the male and female terminals 5 and 4 can be absorbed to reduce wear or abrasion between them.

Description: This invention relates to an electrical connector and more particularly to an electrical connector which secures a male terminal to a male connector housing. For convenience of explanation, a construction of a prior electrical connector will be explained by referring to FIG. 12. FIG. 12 is a longitudinal sectional view of the prior electrical connector. Heretofore, an electrical connector having a male connector housing 1 in which male terminals 5 are secured by an insert molding or a pressingly insertion is known as a connector for directly connecting devices or a connector for a printed circuit board. The conventional male connector housing 1, as shown in FIG. 12, supports the male terminal 5 with its rear end being directly attached to a printed circuit board B and its front end passing through and being fixed in a rear wall 12 of the housing 1. The male terminal 5 is adapted to be coupled to a female terminal 4 mounted in a female connector housing 2. The housing is provided on its lower portion with a support base 19 which serves to horizontally support the housing 1 on the board B. However, as shown exaggeratedly in FIG. 12, in the case that such type of the electrical connector is used for a wiring in a motive vehicle, vibrations in the motive vehicle are transferred to the female terminal 4 through a cable W. Then, misalignment of axes of the male and female terminals 5 and 4 causes a friction in a contacting portion of them, thereby wearing or abrading the contacting portion. Consequently, both terminals will be brought into a bad contacting state during long term use. We are aware of FR-A-2 396 438 in which co-operating electrical contact members are resiliently mounted in bores in complementary housings to compensate for relative movement between the housings. We are also aware of US-A-4 697 864 which discloses an electrical connector forming the pre-characterising portion of Claim 1. According to our invention in an electrical connector comprising a female housing adapted to receive a plurality of female terminals, and a male housing having a front hood, and a rear wall, and male terminals attached to the male housing, in which the male terminals are adapted to contact the female terminals when the female housing is in the front hood in a coupled position, the rear wall has a plurality of stepped holes, each comprising a reduced diameter portion and an enlarged diameter portion located inwardly of the reduced diameter portion in an axial direction of the stepped hole, and elastic members having bores therethrough are received in the stepped holes, each male terminal extending through the bore in a respective elastic member and being attached and secured to the male housing by a respective one of the reduced portions, whereby the male terminals are elastically supported by the elastic members to facilitate and maintain a good contacting state with the female terminals in the coupled position. Any vibrations which might otherwise cause abrasions between contacting portions of the male and female terminals are also absorbed by the elasticity of the elastic members. Preferably the elastic members are housed in the enlarged diameter portions. Thus the male terminals are mounted in the reduced diameter portions by co-operation into the rear wall itself, and displacement of the terminals in a radial direction is permitted by displacement of the elastic members. When the female connector housing is coupled to the male connector housing the male terminals are connected to the female terminals, respectively. At this time, the male terminal is secured in the reduced diameter part of the stepped hole at its one end and supported in the female terminal at its other end. An intermediate portion of the male terminal between the reduced diameter part of the female terminal may be supported in the enlarged diameter part with a given clearance. In this coupled position, even if the female terminal is displaced due to vibrations, the male terminal can elastically deflect in the enlarged part of the stepped hole in accordance with the displacement of the female terminal. Consequently, an abnormal contacting pressure caused by vibrations at contacting portions of the male and female terminals can be absorbed to reduce wear or abrasion between them. Since one end of the male terminal is elastically supported through the elastic member in the stepped hole and the other end of the male terminal is supported in the female terminal, in this coupled position, even if the female terminal is displaced due to vibrations, the elastic member deflects so that the male terminal is displaced in the stepped hole. Consequently, the male terminal is elastically displaced in accordance with the displacement of the female terminal. An abnormal contacting pressure caused by vibrations at contacting portions of the male and female terminals can be absorbed to reduce wear or abrasion between them. In the electrical connector of the present invention, it is possible to maintain a good contacting state of the terminals for a long term by supporting the male terminal in the reduced diameter part of the stepped hole. Also, it is possible to maintain a good contacting state of the terminal for a long term by elastically supporting the male terminal through the elastically supporting the male terminal through the elastic member in the stepped hole. FIG. 1 is an exploded perspective view of an embodiment of electrical connector in accordance with the present invention; FIG. 2 is a longitudinal sectional view of a first example of an electrical connector useful for understanding the securing of terminals in a male connector housing; FIG. 3 is a longitudinal sectional view of the connector as shown in the example, illustrating exaggeratedly a coupled position of male and female connector housings; FIG. 4 is a longitudinal sectional view of a second embodiment of the male connector housing; FIG. 5 is a longitudinal sectional view of a third embodiment of the male connector housing; FIG. 6 is a longitudinal sectional view of a fourth embodiment of the male connector housing; FIG. 7 is a longitudinal sectional view of a second example of a male connector housing of an electrical connector; FIG. 8 is a longitudinal sectional view of a fifth embodiment of the male connector housing; FIG. 9 is a longitudinal sectional view of a sixth embodiment of the male connector housing; FIG. 10 is a longitudinal sectional view of the connector, illustrating exaggeratedly a coupled position of male and female connector housing in the sixth embodiment; FIG. 11 is a longitudinal sectional view of an seventh embodiment of the male connector housing; and FIG. 12 is a longitudinal sectional view of a prior electrical connector, illustrating exaggeratedly a coupled position of male and female connector housings. Embodiments of an electrical connector in accordance with the present invention will be explained below by referring now to FIGS. 1 to 11. A first example and second example of an electrical connector, which is mounted on a printed circuit board, is described by referring to FIGS. 2, 3 and 7. In this examples the attachement of the terminals to the housing is explained without reference to the elastic member as claimed. As shown in FIG. 1, in the first embodiment of the electrical connector, a female connector housing 2 is adapted to be received in a male connector housing a female terminal 4 attached to a distal end of an electrical cable W is adapted to be inserted into one of terminal accommodating holes 3 in the female connector housing 2. The female terminal 4 is made by a conventional manner of bending a metal sheet into a box like body, into which a plate like male terminal 5 can be inserted. The male connector housing 1, as shown in FIG. 2, is formed into a front side open box having a front hood portion 11 and a rear wall portion 12. A rectangular coupling space 14 is defined by the interior of the front hood portion 11 and an inner face 13 of the rear wall portion 12. The rear wall portion 12 is provided on an outer face with bosses 15. A cylindrical stepped hole 16 extends through each boss 15 and the rear wall portion 12 and has a depth (length) L. The stepped hole 16 includes a reduced diameter part 161 (length L1) at an outer side of the boss 15 and an enlarged diameter part 162 (length L2) at an inner side of the rear wall portion 12. A middle portion of the male terminal 5 is secured in the reduced diameter part 161 by an insert molding. A distal end of the male terminal 5 projects through the enlarged diameter portion 162 into the coupling space 14 by a length required for being coupled to the female terminal 4. That is, the male terminal 5 is secured in the reduced diameter part 161, passes through the enlarged part 162 with a given clearance, and extends toward the coupling space 14. The hood portion 11 is provided on its rear side with a support base 19 which serves to support the male connector housing 1 on the printed circuit board B horizontally. The male terminal 5 is made of a thin conductive metal plate and bent downwardly by an angle of 90° at a rear side from the boss 15. A lower end of the terminal 5 is inserted into and secured in the printed circuit board B shown by a two dot chain line in FIG. 2. When the female connector housing 2 is coupled into the coupling space 14 in the male connector housing 1, as shown in FIG. 3, the male terminal 5 is coupled into the female terminal 4. Then, the middle portion of the male terminal 5 is secured in the reduced diameter part 161 of the stepped hole 16 through the length L1 while the other end of the male terminal 5 passes through the enlarged diameter part 162 of the hole 16 with a given clearance along the distance L2 and enters into the female terminal 4 to be secured therein. In this coupled position, when the female connector housing 2 is inclined upwardly in the coupling space 14 in the male connector housing 1 due to vibrations, the male terminal 5 is elastically deflected at a portion corresponding to the length L2 in accordance with a displacement of the female terminal 4, as shown exaggeratedly in FIG. 3, thereby absorbing an abnormal contacting pressure at a contacting portion of the male and female terminals 5 and 4 on account of the vibrations. This results in relief of wear or abrasion. Although it is not illustrated in the drawing, in the case that the female terminal 4 is displaced upwardly or downwardly in the female connector housing 2, the same effect can be obtained. A second embodiment is substantially the same as the first example. As shown in FIG. 4, a difference between them is to dispose an elastic member 20a made of an elastic rubber in the enlarged diameter part 162 of the stepped hole 16. Thus, in the second embodiment, since the male terminal 5 is elastically supported by the elastic member 20a even if any external force is applied to a distal end of the male terminal 5 before the female connector housing 2 is coupled into the coupling space 14 in the male connector housing 1, the male terminal is not deformed eternally. Also, since the male terminal 5 is elastically supported in the enlarged diameter part 162, it is not necessary to extend the length L2 of the reduced diameter part 161 in the boss 15, it is possible to hold a plurality of male terminals 5 straightly toward an inserting direction of the female connector housing 2, it is not necessary to make the male connector housing 2 a large size, and it is possible to readily insert the female connector housing 2 into the male connector housing 1. A third embodiment is substantially the same as the first embodiment. As shown in FIG. 5, a difference between them is to mount a spring 20b on the male terminal 5 and to dispose the spring 20b in the enlarged diameter part 162 of the stepped hole 16. Thus, in the third embodiment, it is possible to prevent an eternal deformation of the male terminal 5, to hold it straightly, and to smooth by insert the female connector housing 2 into the male connector housing 1, by the same manner as the second embodiment. A fourth embodiment is substantially the same as the second embodiment. As shown in FIG. 6, a difference between them is to provide an elastic piece 20c, which projects toward the coupling space 14, in the enlarged diameter part 162 of the stepped hole 16 and to elastically support the male terminal 5 in the part 162 by means of the piece 20c. Thus, in the fourth embodiment, it is possible to prevent an eternal deformation of the male terminal 5, to hold it straightly, and to smoothly insert the female connector housing 2 into the male connector housing 1, by the same manner as the second embodiment. As shown in FIG. 7, in a second example without showing the elastic member as claimed, the enlarged diameter part 162 of the stepped hole 16 is provided with a second reduced part 163 which serves to secure the male terminal 5. Since the male terminal 5 is secured in the first and second reduced diameter parts 161 and 163, it is possible to hold the male terminal 5 straightly toward an inserting direction of the female connector housing 2, by the same manner as the second embodiment. A fifth embodiment, as shown in FIG. 8, is a vertical type of an electrical connector which stands on the printed circuit board B vertically. A pair of support bases 19a projecting from opposite sides of a rear wall portion 12a support a male connector housing la on the printed circuit board B vertically. A male terminal 5a made of a thin metal plate projects straightly downwardly from a boss 15a and a lower end of the male terminal 5a is inserted into and soldered in an aperture in the printed circuit board B to fix the connector housing la on the board B vertically. By the same manner as the first embodiment, a cylindrical stepped hole 16a is formed in each boss 15a and the rear wall portion 12a and has a depth (length) L. The stepped hole 16a includes a reduced diameter part 161a having a depth (length) L1 at an outer side of the boss 15a and an enlarged diameter part 162a having a depth (length) L2 at an inner side of the rear wall portion 12a. The male terminal 5a is secured in the reduced diameter part 161a by an insert molding and passes through the enlarged diameter part 162a with a given clearance. In the fifth embodiment, by the same manner as the first example, when the male terminal 5a is coupled into a female terminal not shown, a middle portion of the male terminal 5a is secured in the reduced diameter part 161a and a distal end of the terminal 5a is coupled into and supported in the female terminal through the distance L2 in the enlarged diameter part 162a. As shown exaggeratedly in FIG. 8, the male terminal 5a is elastically deflected at the portion of the length L2 to release an abnormal contacting pressure on account of the vibrations onto the male terminal 5a. The reduced diameter part 161a secures the male terminal 5a in the sixth embodiment, and an elastic member is to be disposed in the enlarged diameter part 162a by the same manner as in the previous embodiments. Although the male terminal 5 or 5a is secured in the reduced diameter part 161 or 161a by the insert molding in the first through fifth embodiments, the terminal may be secured in the part by pressingly fitting. It will be preferable to utilize any one of the second to fifth embodiments in order to direct the distal end of the male terminal 5 to the inserting direction of the female connector housing 2 when pressingly inserting the male terminal 5 into the reduced diameter part 161. Although the bosses 15 or 15a are provided on the outer side of the rear wall portion 12 or 12a and the reduced diameter part 161 or 161a is formed in the boss 15 or 15a in the first through fifth embodiments, the rear wall portion 12 or 12a may be formed into a thick wall so that the stepped hole 16 or 16a is formed in the wall. A male connector housing 1 in a sixth embodiment, as shown in FIG. 9, includes a rectangular hood portion 11 adapted to receive a female connector housing 2 and a rear wall portion 12 integrally formed on a rear side of the hood portion 11. A rectangular coupling space 14 is defined by the interior of the hood portion 11 and an inner face of the rear wall portion 12. The rear wall portion 12 is provided on an outer face with a boss 15 projecting backwardly to define a thickness L. A stepped hole 16 extends from the inner face 13 of the rear wall portion 12 to the outer face of the boss 15. The stepped hole 16 includes a reduced diameter part 161 having a depth (length) L1 at an outer side of the boss 15 and an enlarged diameter part 162 having a depth (length) L2 at an inner side of the rear wall portion 12. An elastic member 20d such as a rubber ring is inserted in the stepped hole 16. A male terminal 5 passes axially through the elastic member 20d and projects straightly in a coupling direction in the coupling space 14 and a distal end of the male terminal 5 extends by a length enough to enter into a female terminal 4. That is, the male terminal 5 is elastically supported by secured in the stepped hole 16 through a distance L and projects into the coupling space 14. The hood portion 11 is provided on its rear side with a support base 19 which serves to support the male connector housing 1 on the printed circuit board B horizontally. The male terminal 5 is made of a thin conductive metal plate and bent downwardly by an angle of 90° at a rear side from the boss 15. A lower end of the terminal 5 is inserted into and soldered in an aperture in the printed circuit board B shown by a two dot chain line in FIG. 9. When the female connector housing 2 is being coupled into the coupling space 14 in the male connector housing 1 in the sixth embodiment, as shown in FIG. 10, the male terminal 5 pushes the female terminal 4. The reduced diameter part 161 holds the male terminal 5 through the elastic member 20d not to be pushed back by the female terminal 4. Then, the male terminal 5 is coupled to the female terminal 4. At this time, the male terminal 5 is elastically secured by the elastic member 20d in the stepped hole 16 through the thickness L and clamped at its other end in the female terminal 4. In this coupled position, when the female connector housing 2 is inclined upwardly in the coupling space 14 in the male connector housing 1 due to vibrations, the male terminal 5 along with the elastic member 20d are elastically deformed upwardly, as shown exaggeratedly in FIG. 10. Particularly, in this embodiment, the male terminal 5 is elastically deformed at a portion of the length L in accordance with a displacement of the female terminal 4, thereby absorbing an abnormal contacting pressure at a contacting portion of the male and female terminals. This results in relief of wear or abrasion. Although it is not illustrated in the drawing, in the case that the female terminal 4 is displaced upwardly or downwardly in the female connector housing 2, the same effect can be obtained. In the sixth embodiment, the boss 15 is provided on the outer face of the rear wall portion 12 and the stepped hole is formed through the boss 15 and rear wall portion. <Example 8> A seventh embodiment shown in FIG. 11 is a vertical type of an electrical connector. In the vertical type of the electrical connector, a pair of support bases 19a projecting from opposite sides of a rear wall portion 12a support a male connector housing la on the printed circuit board B vertically. A male terminal 5a made of a thin metal plate projects straightly downwardly from a boss 15a and a lower end of the male terminal 5a is inserted into and soldered in an aperture in the printed circuit board B to fix the male connector housing la on the board B vertically. In this vertical type, since the male terminal 5a is substantially supported in the reduced diameter part 161a and elastically supported by the elastic member 20d through the thickness L, the male terminal 5a can be elastically deflected as shown by two dot chain lines in FIG. 11 thereby releasing an abnormal contacting pressure due to vibrations at the contacting portion of the male and female terminals.

Claims: An electrical connector comprising a female housing (2) adapted to receive a plurality of female terminals (4), and a male housing (1) having a front hood (11), and a rear wall (12), and male terminals (5) attached to the male housing (1), in which the male terminals (5) are adapted to contact the female terminals (4) when the female housing (2) is in the front hood (11) in a coupled position, characterised in that the rear wall (12) has a plurality of stepped holes (16), each comprising a reduced diameter portion (161) and an enlarged diameter portion (162) located inwardly of the reduced diameter portion (161) in an axial direction of the stepped hole, and elastic members (20a - 20d) having bores therethrough are received in the stepped holes, each male terminal (5) extending through the bore in a respective elastic member and being attached and secured to the male housing (1) by a respective one of the reduced portions (161), whereby the male terminal (5) are elastically supported by the elastic members (20d) to facilitate and maintain a good contacting state with the female terminals (4) in the coupled position. The electrical connector of Claim 1, wherein the elastic members (20a) are housed in the enlarged diameter portions (162).

Inventors: ATSUMI KEIGO, SAIJO EIJI, ATSUMI, KEIGO, SAIJO, EIJI, ATSUMI, KEIGO, C/O SUMITOMO WIRING SYST., LTD., SAIJO, EIJI, C/O SUMITOMO WIRING SYST., LTD.
Applicants: SUMITOMO WIRING SYSTEMS, SUMITOMO WIRING SYSTEMS, LTD.
Application year: 1994
Main classification: H01R23
IPC codes: H01R13